I had my eyes on a biometric pistol safe for quite some time. Who wouldn't want such a fixture? After all, it is something straight out of a James Bond film. Unfortunately my finances and my wish list were in two different places so I was going to have to go without...or so I thought.

I happened to be browsing clearance items at the mall one day and ran across a Craftsman Fingerprint Keyless Entry Pad for a garage door. (Sears item #53555) Thinking that these might work for my pistol safe I bought them all. (They have been discontinued by Sears, search eBay for "Craftsman Fingerprint")

So I had the biometric half of the project, that was the hard part. Now I needed a safe. I scoured eBay for months looking for a non-working pistol safe and finally found one. The key pad was broken and the price was right. I had the other half of my project!

So I sat down in my workshop and started thinking about how to put it all together. I poked around for days on the circuit board of the fingerprint reader. I finally found a spot that only sent a "signal" when the proper fingerprint was swiped. It never sent a signal if an improper print was swiped. Only problem was that it did send a very short signal when the circuit was first powered up. I needed a circuit to tell the difference between the "power on pulse" and the "correct print pulse".

I turned to the internet for help. I found a forum and started asking questions. Here is what I came up with.

This is what you will see when you first open the fingerprint reader. You will need to flip the circuit board over.

The red arrows indicate the pin and pad that can be used to take the "proper print signal" from. I used a very thin insulated wire and threaded it up and down through a few of the holes surrounding the IC so if the wire was tugged during reassembly the solder joint would not be strained.

To convert my signal to pulse that would open the door of my safe required this circuit. It is based around the CD40106B. The "6v" marks indicate that the circuit is running off of the same 4 AA batteries that power the fingerprint unit. The "12v" marks indicate a separate battery pack that is used to power the latch only.

Here is the final product. I am being a bit vague on the exact details of this particular build on purpose to protect the security of the design but with the schematics and descriptions I have given anyone should be able to recreate it. When the proper print is swiped the door opens and reveals any valuables you want to hide inside!

If you want to read all the details instead of just this crappy write-up, check out the original thread. Fingerprint Pistol Safe